This bloke did a full clean and service on mine a few years ago. I was miffed when it came back because the rangefinder was not smooth all the way and it started to stiffen up again with use. So sent it back, he said there was some of the old lubricant still in the movement that he had missed, came back working perfectly and has done since, however this time it came back with a with a fiber between the glass, so I had to send it back again but again he got it out quickly.
Went to use the self timer and it stuck when trying to operate it, gently forced it back and was frightened to use it again, I decided I was not going to return it another time. But I did try it again last year when changing a film and it worked perfectly then and has done since.
He did do the job because she works like new now, the camera was my late fathers who was a meticulous man, its only problem was it did not like moving from England to the heat of the southern USA. The rangefinder gummed up.
On a side note, I used some cotton buds and put leather conditioner on the outside of the bellows, they are so supple and soft. Do not put too much on but it will stop the bellows cracking. Too much and it will leach through onto the inside. I also had her covered with black GRIPTAC, because the old covering was shiny and slippery made it difficult to get a good hold of, so I took the old covers off and thoroughly cleaned the exterior, then sent it off to be covered. The GRIPTAC is fantastic stuff, no more slippery holding.
So there is my experience. Mine makes beautiful BW images, the glass is superb.
Good luck and cheers.